P2P communication techniques in which direct communication is performed between two terminals are known. Here, in a case in which communication is performed between terminals using a P2P communication technique, there are cases where direct communication between terminals cannot be performed depending on configuration of networks to which the terminals are connected. For example, in a case in which two terminals belong to different private networks respectively, packets may be discarded depending on the specification of NAT (Network Address Translation), so that direct communication between terminals cannot be performed. In view of this, there is a technique called ICE (Interactive Connectivity Establishment) as a technique for enabling communication between terminals belonging to a private network (see, for example, non-patent document 1). The ICE makes it possible to perform direct communication between terminals by exchanging, between terminals, via a signaling server, an address of the terminal itself, an address in the public network side of NAT, and an address of a relay apparatus placed on a public network. Also, as a signaling protocol using the ICE in the WebRTC technique, JSEP (Javascript (registered trademark) trademark) Session Establishment Protocol) is known (refer to non-patent document 2, for example).